Abstract
The study determined the differences in the performance of grade 8 learners who were taught Natural Sciences in their home language (Afrikaans) and those taught in English (second language). In a sequential mixed method research design 200 grade 8 learners and their four teachers were selected to participate in the study. Quantitative data was collected through the analysis of learners' scores in four of the formative assessments administered by their teachers and qualitative data was obtained from the analysis of learners' responses to open ended questions. Quantitative and qualitative data were analysed statistically and content analysis respectively. Findings showed that learners taught in the second language performed better than those taught in their home language and that learners who learn in a second language (English) could express themselves better than those learning in home language (Afrikaans). Findings have implications on language in education policy and pre-service and in-service teacher development.